Replace the raw ~tokens/~tokens percentage with a compact context-window bar: green = carried cache, red = cache lost by switching, dim = remaining window. The percentage label is the source-lane cache drop.\n\n- Track active lane from the last successful assistant message.\n- Evaluate switch impact against that lane instead of the destination alone.\n- Fall back to the old concise text when context usage is unavailable.\n- Update tests and docs; bump to 0.2.0.